A strip of closures and individual closures having different configurations of bag neck-confining apertures entered through openings in opposite edges of the closures. The differing configurations of the bag neck-confining apertures can be different sizes and/or different shapes, and preferably are in the opposite sides of a strip of closures so that the differing bag neck-confining apertures can be exposed to oncoming bags merely by flipping the strip over 180 degrees.